New Seat Details - Letchworth and Royston

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Letchworth and Royston been in force at that time. The basic idea of the calculation is to look at the district council wards which make up the new seat, and estimate how they voted in 2017. This estimate is based on the recent local election results in those wards, with adjustments made to allow for different turnouts and different voting patterns for local and general elections.

In many cases, wards are divided between several old constituencies or between new constituencies. So the same ward may be shown more than once, but the electorate shown will reflect that ward sub-section.

Election results from a recent local election are given. This is usually the local election closest to 2015 from the period 2012-2015. For multiple-member wards, the votes shown are the sum of the votes cast for all candidates of each party. A negative number indicates candidate(s) elected unopposed.

Calculation method

There are two problems with using the raw (actual) local election results to imply general election results ward-by-ward. Firstly, turnout can be different between local and general elections, which means that the total number of local votes cast does not equal the number of votes cast in each old seat at the general election. To correct for this, we adjust the local votes to match the general election turnout. Each ward's result is scaled, whilst keeping constant the percentage support for each party, so that the total turnout adds up to the old seat's general election turnout. All wards in the old seat are assumed to have the same percentage turnout.

Party	Implied 2017 Votes	Implied 2017 Share
CON	33,196	56.2%
LAB	16,914	28.6%
LIB	6,042	10.2%
Green	2,894	4.9%
CON Majority	16,282	27.6%

Secondly, even though we now have the correct number of votes in the old seat, the party totals will not match the general election result. Some parties do better at the local election than the general election, and others do vice versa. We call these strong and weak parties respectively. The next step is to transfer votes from strong parties to weak parties. This is done by taking votes proportionally away from strong parties and putting them in a transfer pool. For instance if a party got 12,500 local votes, but only 10,000 general election votes, it will lose 20% over all the wards. These votes in each ward will be put in the ward's transfer pool and allocated to the weak parties. Weak parties will get votes transferred to them in proportion to the votes they need over the old seat. For instance, if two weak parties need 4,000 and 1,000 votes respectively, the first party will get 80% of each ward's transfer pool and the second party will get 20% of each ward's transfer pool. The transfer of votes between parties is done using the Electoral Calculus Transition Model.

Letchworth and Royston: Map

List of old seats forming part of Letchworth and Royston

Old seat: Cambridgeshire South

The table shows the transfer-adjusted results for each ward in the old seat of Cambridgeshire South, as well as showing which new seat each ward is in.

Old seat: Cambridgeshire South				Transfer-adjusted Results
District	Ward	Electorate 2017	New Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	NAT Votes	MIN Votes	OTH Votes	Total Votes
Cambridge	Queen Edith's	5,491	Cambridge	1,866	1,913	1,434	0	170	0	0	0	5,383
South Cambridgeshire	Bar Hill	3,638	Cambridgeshire South	1,547	891	456	0	92	0	0	0	2,986
South Cambridgeshire	Barton	1,887	Cambridgeshire South	907	343	190	0	44	0	0	0	1,484
South Cambridgeshire	Bassingbourn	3,364	Letchworth and Royston	1,782	801	338	0	82	0	0	0	3,003
South Cambridgeshire	Bourn	7,462	Cambridgeshire South	3,232	2,009	719	0	145	0	0	0	6,105
South Cambridgeshire	Caldecote	1,829	Cambridgeshire South	654	307	462	0	21	0	0	0	1,444
South Cambridgeshire	Comberton	1,761	Cambridgeshire South	804	339	213	0	40	0	0	0	1,396
South Cambridgeshire	Cottenham	5,954	Cambridgeshire South	2,479	1,332	815	0	141	0	0	0	4,767
South Cambridgeshire	Duxford	2,089	Cambridgeshire South	964	412	242	0	39	0	0	0	1,657
South Cambridgeshire	Fowlmere and Foxton	1,870	Cambridgeshire South	861	343	183	0	46	0	0	0	1,433
South Cambridgeshire	Gamlingay	3,850	Cambridgeshire South	1,371	646	858	0	36	0	0	0	2,911
South Cambridgeshire	Girton	3,232	Cambridgeshire South	1,385	783	441	0	85	0	0	0	2,694
South Cambridgeshire	Hardwick	1,995	Cambridgeshire South	799	421	327	0	41	0	0	0	1,588
South Cambridgeshire	Harston and Hauxton	1,863	Cambridgeshire South	687	303	417	0	20	0	0	0	1,427
South Cambridgeshire	Haslingfield and The Eversdens	2,141	Cambridgeshire South	720	327	499	0	23	0	0	0	1,569
South Cambridgeshire	Longstanton	2,336	Cambridgeshire South	1,018	347	190	0	19	0	0	0	1,574
South Cambridgeshire	Melbourn	4,170	Letchworth and Royston	1,455	768	1,061	0	41	0	0	0	3,325
South Cambridgeshire	Meldreth	2,056	Letchworth and Royston	643	374	467	0	18	0	0	0	1,502
South Cambridgeshire	Orwell and Barrington	1,892	Cambridgeshire South	677	309	361	0	32	0	0	0	1,379
South Cambridgeshire	Papworth and Elsworth	4,091	Cambridgeshire South	1,660	773	390	0	71	0	0	0	2,894
South Cambridgeshire	Sawston	5,272	Cambridgeshire South	2,280	1,337	516	0	108	0	0	0	4,241
South Cambridgeshire	Swavesey	1,827	Cambridgeshire South	889	347	201	0	20	0	0	0	1,457
South Cambridgeshire	The Abingtons	1,764	Cambridgeshire South	870	310	155	0	18	0	0	0	1,353
South Cambridgeshire	The Mordens	1,888	Letchworth and Royston	855	368	186	0	17	0	0	0	1,426
South Cambridgeshire	The Shelfords and Stapleford	5,577	Cambridgeshire South	2,250	1,222	727	0	127	0	0	0	4,326
South Cambridgeshire	Whittlesford	2,069	Cambridgeshire South	975	355	251	0	18	0	0	0	1,599
	Total	81,368		33,630	17,680	12,099	0	1,514	0	0	0	64,923

The full details of these calculations are given on the Cambridgeshire South seat details page. Click on "Show workings".

Old seat: Hertfordshire North East

The table shows the transfer-adjusted results for each ward in the old seat of Hertfordshire North East, as well as showing which new seat each ward is in.

Old seat: Hertfordshire North East				Transfer-adjusted Results
District	Ward	Electorate 2017	New Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	NAT Votes	MIN Votes	OTH Votes	Total Votes
East Hertfordshire	Braughing	2,061	Letchworth and Royston	1,024	315	60	0	88	0	0	0	1,487
East Hertfordshire	Buntingford	4,289	Letchworth and Royston	2,084	736	163	0	157	0	0	0	3,140
East Hertfordshire	Hertford Rural North	1,769	Welwyn Hatfield	980	232	52	0	72	0	0	0	1,336
East Hertfordshire	Hertford Rural South	1,968	Welwyn Hatfield	1,077	258	103	0	43	0	0	0	1,481
East Hertfordshire	Little Hadham	1,857	Letchworth and Royston	1,032	270	53	0	89	0	0	0	1,444
East Hertfordshire	Mundens and Cottered	1,927	Letchworth and Royston	1,060	305	47	0	39	0	0	0	1,451
East Hertfordshire	Puckeridge	2,032	Letchworth and Royston	991	386	77	0	89	0	0	0	1,543
East Hertfordshire	Thundridge and Standon	2,180	Letchworth and Royston	1,284	391	72	0	52	0	0	0	1,799
East Hertfordshire	Walkern	2,085	Stevenage	1,134	370	62	0	47	0	0	0	1,613
East Hertfordshire	Watton-at-Stone	1,880	Stevenage	935	288	69	0	67	0	0	0	1,359
North Hertfordshire	Arbury	2,045	Letchworth and Royston	1,059	282	149	0	98	0	0	0	1,588
North Hertfordshire	Baldock East	2,251	Letchworth and Royston	930	382	290	0	80	0	0	0	1,682
North Hertfordshire	Baldock Town	5,647	Letchworth and Royston	2,500	1,261	266	0	267	0	0	0	4,294
North Hertfordshire	Ermine	1,949	Letchworth and Royston	1,102	261	62	0	94	0	0	0	1,519
North Hertfordshire	Letchworth East	4,222	Letchworth and Royston	1,352	1,450	205	0	213	0	0	0	3,220
North Hertfordshire	Letchworth Grange	5,492	Letchworth and Royston	2,029	1,658	345	0	225	0	0	0	4,257
North Hertfordshire	Letchworth South East	5,415	Letchworth and Royston	2,204	1,600	245	0	212	0	0	0	4,261
North Hertfordshire	Letchworth South West	5,910	Letchworth and Royston	2,554	1,217	498	0	316	0	0	0	4,585
North Hertfordshire	Letchworth Wilbury	3,905	Letchworth and Royston	1,313	1,413	192	0	169	0	0	0	3,087
North Hertfordshire	Royston Heath	4,166	Letchworth and Royston	1,754	740	395	0	154	0	0	0	3,043
North Hertfordshire	Royston Meridian	4,078	Letchworth and Royston	1,911	706	354	0	167	0	0	0	3,138
North Hertfordshire	Royston Palace	3,964	Letchworth and Royston	1,570	994	319	0	153	0	0	0	3,036
North Hertfordshire	Weston and Sandon	1,637	Letchworth and Royston	708	236	198	0	74	0	0	0	1,216
	Total	72,729		32,587	15,751	4,276	0	2,965	0	0	0	55,579

The full details of these calculations are given on the Hertfordshire North East seat details page. Click on "Show workings".

New seat: Letchworth and Royston

District	Ward	Electorate 2017	Old Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	NAT Votes	MIN Votes	OTH Votes	Total Votes
New seat: Letchworth and Royston
East Hertfordshire	Braughing	2,032	Hertfordshire North East	1,024	315	60	0	88	0	0	0	1,487
East Hertfordshire	Buntingford	4,291	Hertfordshire North East	2,084	736	163	0	157	0	0	0	3,140
East Hertfordshire	Little Hadham	1,973	Hertfordshire North East	1,032	270	53	0	89	0	0	0	1,444
East Hertfordshire	Mundens and Cottered	1,983	Hertfordshire North East	1,060	305	47	0	39	0	0	0	1,451
East Hertfordshire	Puckeridge	2,110	Hertfordshire North East	991	386	77	0	89	0	0	0	1,543
East Hertfordshire	Thundridge and Standon	2,457	Hertfordshire North East	1,284	391	72	0	52	0	0	0	1,799
North Hertfordshire	Arbury	2,172	Hertfordshire North East	1,059	282	149	0	98	0	0	0	1,588
North Hertfordshire	Baldock East	2,300	Hertfordshire North East	930	382	290	0	80	0	0	0	1,682
North Hertfordshire	Baldock Town	5,870	Hertfordshire North East	2,500	1,261	266	0	267	0	0	0	4,294
North Hertfordshire	Ermine	2,076	Hertfordshire North East	1,102	261	62	0	94	0	0	0	1,519
North Hertfordshire	Letchworth East	4,402	Hertfordshire North East	1,352	1,450	205	0	213	0	0	0	3,220
North Hertfordshire	Letchworth Grange	5,818	Hertfordshire North East	2,029	1,658	345	0	225	0	0	0	4,257
North Hertfordshire	Letchworth South East	5,824	Hertfordshire North East	2,204	1,600	245	0	212	0	0	0	4,261
North Hertfordshire	Letchworth South West	6,266	Hertfordshire North East	2,554	1,217	498	0	316	0	0	0	4,585
North Hertfordshire	Letchworth Wilbury	4,219	Hertfordshire North East	1,313	1,413	192	0	169	0	0	0	3,087
North Hertfordshire	Royston Heath	4,160	Hertfordshire North East	1,754	740	395	0	154	0	0	0	3,043
North Hertfordshire	Royston Meridian	4,289	Hertfordshire North East	1,911	706	354	0	167	0	0	0	3,138
North Hertfordshire	Royston Palace	4,151	Hertfordshire North East	1,570	994	319	0	153	0	0	0	3,036
North Hertfordshire	Weston and Sandon	1,662	Hertfordshire North East	708	236	198	0	74	0	0	0	1,216
South Cambridgeshire	Bassingbourn	3,944	Cambridgeshire South	1,782	801	338	0	82	0	0	0	3,003
South Cambridgeshire	Melbourn	4,366	Cambridgeshire South	1,455	768	1,061	0	41	0	0	0	3,325
South Cambridgeshire	Meldreth	1,972	Cambridgeshire South	643	374	467	0	18	0	0	0	1,502
South Cambridgeshire	The Mordens	1,873	Cambridgeshire South	855	368	186	0	17	0	0	0	1,426
	Total	80,210		33,196	16,914	6,042	0	2,894	0	0	0	59,046

And these are the implied results for 2017 for the new seat of Letchworth and Royston. Please note that the wards used are those of 2015 in order to be consistent with those used by the Boundary Commissions.

Implied MP at 2017:	Oliver Heald (CON)
County/Area:	Hertfordshire (Anglia)
Electorate:	80,210
Turnout:	73.6%

Letchworth and Royston: New Boundaries 2018 Calculation

Letchworth and Royston: Overview

Introduction